1. Field of the Invention
The invention relates to a book scanner with a minimized scan margin, and more particularly to a book scanner with a zero scan margin.
2. Description of the Related Art
The conventional book scanners can be classified into two types according to the moving direction of the scanning module and the extending direction of the binding section of a book placed on the book scanner. The first type has a scanning module that moves in a direction parallel to the extending direction of the binding section of the book. The second type has a scanning module that moves in a direction perpendicular to the extending direction of the binding section of the book. The invention is to solve the problems of these two types of book scanners.
In order to facilitate the process of scanning an open book, which includes documents that are bound together, the book scanner usually has a sloped surface and a transparent platen to support the open book so as to obtain the better scan quality.
In order to acquire the image close to the binding section, beside that the problem of the insufficient and nonuniform illumination on the binding section has to be overcome, the structure of the book scanner has to be modified in order to minimize the scan margin and consequently obtain a binding section image of better quality.
The Taiwan Patent Publication No. 275415 discloses a book scanner including the aforementioned sloped surface and transparent platen. However, because the sloped surface and the transparent platen have to be fixed together using an opaque component, the scanner cannot scan the binding section of the book. The shortest distance from a scan region, which defines the area the prior art book scanner scans, to the ridge defined by the sloped surface and the transparent platen ranges from 4 to 6 millimeters or often greater than 6 millimeters. Therefore, a quality image close to the binding section cannot be acquired. If a book is very thick and cannot be completely spread out, the image close to the binding section cannot be acquired by the conventional book scanner, and image distortion tends to occur.